Insect infestation in wooden icon

Anne Lane <alane [at] charlottemuseum__org> writes

>I received a heads-up today that I will be receiving a call
>concerning a possible insect infestation in a wooden icon. I am
>assuming it is painted on wood, possibly with gold leaf. I have no
>idea about its age, country of origin, etc. My question concerns the
>two major methods of treating insect problems that I am aware of,
>freezing and anoxia.

Please note that there is a variety of materials on an wooden icon,
including wood, gesso, gold leaf, paint and varnish. In many cases,
icons are painted on canvas adhered onto the wood. I would not
recommend freeze drying since the different contraction rates could
cause cracking.

Do keep in mind that in most cases even if only a few exit holes are
visible, the damage in the interior is much more extended; the holes
are just the ends of the tunnels dug by the worms, which live in the
wood from 1 to an amazing 10 years or more. This depends on many
factors, such as RH, temperature, type of wood and the species of
the insect.

Whenever I treat icons I always use woodworm killers in liquid form.
First clean insect debris mechanically wherever possible. Then find
a deep tray at least 5cm longer and wider than your icon. Place a
non-coloured cloth in the tray and impregnate it with liquid
woodworm killer. Make sure that the cloth is wet enough and covers
the whole surface of the bottom of the tray. Then place the icon on
the cloth inside the tray, with the painted surface facing upwards
and the non-painted surface coming in contact to the woodworm-killer
impregnated cloth. Leave it in the tray for several days. The
chemical will be absorbed by the wood and kill the woodworms.

For extra protection of the painted surface, you may consider using
facing paper (non-woven Japanese tissue paper) on the painted
surface, applied with a warm solution of rabbit skin glue in
distilled water, and leave the facing paper on the painted surface
for as long as the icon stays in the tray. After you remove the icon
from the tray, allow a couple of days for it to dry and then remove
the facing paper by wetting it with distilled water and pulling it
gently. Make sure you do not touch the object with bare hands since
woodworm killers contain toxic substances, and that there is
adequate ventilation.

Please keep in mind that several insect species lay their eggs in
the exit holes of previous insects, so I recommend that you fill
the holes after the procedure described above. I usually use either
Paraloid B72 30% w/w in acetone, or a warm mixture of melted beeswax
and French chalk, according to the problem. You may also add
pigments in both cases, to imitate the colour of the wood.

Evangelia Kyriazi
Head Conservator
Natural History Museum of the Lesvos Petrified Forest


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                  Conservation DistList Instance 21:65
                   Distributed: Sunday, June 15, 2008
                       Message Id: cdl-21-65-004
                                  ***